/**
 * Original Author -> 杨海健 (taketoday@foxmail.com) https://taketoday.cn
 * Copyright © TODAY & 2017 - 2021 All Rights Reserved.
 *
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see [http://www.gnu.org/licenses/]
 */
package cn.taketoday.context.logger;

import java.text.MessageFormat;
import java.util.HashMap;
import java.util.Map;

//contributors: lizongbo: proposed special treatment of array parameter values
//Joern Huxhorn: pointed out double[] omission, suggested deep array copy

/**
 * From {@link org.slf4j.helpers.MessageFormatter}
 *
 *
 * Formats messages according to very simple substitution rules. Substitutions
 * can be made 1, 2 or more arguments.
 *
 * <p>
 * For example,
 *
 * <pre>
 * MessageFormatter.format(&quot;Hi {}.&quot;, &quot;there&quot;)
 * </pre>
 *
 * will return the string "Hi there.".
 * <p>
 * The {} pair is called the <em>formatting anchor</em>. It serves to designate
 * the location where arguments need to be substituted within the message
 * pattern.
 * <p>
 * In case your message contains the '{' or the '}' character, you do not have
 * to do anything special unless the '}' character immediately follows '{'. For
 * example,
 *
 * <pre>
 * MessageFormatter.format(&quot;Set {1,2,3} is not equal to {}.&quot;, &quot;1,2&quot;);
 * </pre>
 *
 * will return the string "Set {1,2,3} is not equal to 1,2.".
 *
 * <p>
 * If for whatever reason you need to place the string "{}" in the message
 * without its <em>formatting anchor</em> meaning, then you need to escape the
 * '{' character with '\', that is the backslash character. Only the '{'
 * character should be escaped. There is no need to escape the '}' character.
 * For example,
 *
 * <pre>
 * MessageFormatter.format(&quot;Set \\{} is not equal to {}.&quot;, &quot;1,2&quot;);
 * </pre>
 *
 * will return the string "Set {} is not equal to 1,2.".
 *
 * <p>
 * The escaping behavior just described can be overridden by escaping the escape
 * character '\'. Calling
 *
 * <pre>
 * MessageFormatter.format(&quot;File name is C:\\\\{}.&quot;, &quot;file.zip&quot;);
 * </pre>
 *
 * will return the string "File name is C:\file.zip".
 *
 * <p>
 * The formatting conventions are different than those of {@link MessageFormat}
 * which ships with the Java platform. This is justified by the fact that
 * SLF4J's implementation is 10 times faster than that of {@link MessageFormat}.
 * This local performance difference is both measurable and significant in the
 * larger context of the complete logging processing chain.
 *
 * <p>
 * See also {@link #format(String, Object)} and
 * {@link #format(String, Object[])} methods for more details.
 *
 * @author Ceki G&uuml;lc&uuml;
 * @author Joern Huxhorn
 * @author TODAY <br>
 * 2019-11-11 21:40
 */
public final class MessageFormatter {

  static final char DELIM_START = '{';
  static final char DELIM_STOP = '}';
  static final String DELIM_STR = "{}";
  private static final char ESCAPE_CHAR = '\\';

  /**
   * Performs single argument substitution for the 'messagePattern' passed as
   * parameter.
   * <p>
   * For example,
   *
   * <pre>
   * MessageFormatter.format(&quot;Hi {}.&quot;, &quot;there&quot;);
   * </pre>
   *
   * will return the string "Hi there.".
   * <p>
   *
   * @param messagePattern
   *         The message pattern which will be parsed and formatted
   * @param arg
   *         The argument to be substituted in place of the formatting anchor
   *
   * @return The formatted message
   */
  public static String format(String messagePattern, Object arg) {
    return format(messagePattern, new Object[] { arg });
  }

  public static String format(final String messagePattern, final Object[] argArray) {

    if (messagePattern == null || argArray == null) {
      return messagePattern;
    }

    int i = 0;
    int j;
    // use string builder for better multicore performance
    StringBuilder sbuf = new StringBuilder(messagePattern.length() + 50);

    int L;
    for (L = 0; L < argArray.length; L++) {

      j = messagePattern.indexOf(DELIM_STR, i);

      if (j == -1) {
        // no more variables
        if (i == 0) { // this is a simple string
          return messagePattern;
        }
        else { // add the tail string which contains no variables and return the result.
          sbuf.append(messagePattern, i, messagePattern.length());
          return sbuf.toString();
        }
      }
      else {
        if (isEscapedDelimeter(messagePattern, j)) {
          if (isDoubleEscaped(messagePattern, j)) {
            // The escape character preceding the delimiter start is
            // itself escaped: "abc x:\\{}"
            // we have to consume one backward slash
            sbuf.append(messagePattern, i, j - 1);
            deeplyAppendParameter(sbuf, argArray[L], new HashMap<>());
            i = j + 2;
          }
          else {
            L--; // DELIM_START was escaped, thus should not be incremented
            sbuf.append(messagePattern, i, j - 1);
            sbuf.append(DELIM_START);
            i = j + 1;
          }
        }
        else {
          // normal case
          sbuf.append(messagePattern, i, j);
          deeplyAppendParameter(sbuf, argArray[L], new HashMap<>());
          i = j + 2;
        }
      }
    }
    // append the characters following the last {} pair.
    sbuf.append(messagePattern, i, messagePattern.length());
    return sbuf.toString();
  }

  static boolean isEscapedDelimeter(final String messagePattern, final int delimeterStartIndex) {
    return delimeterStartIndex != 0 && messagePattern.charAt(delimeterStartIndex - 1) == ESCAPE_CHAR;
  }

  static boolean isDoubleEscaped(String messagePattern, int delimeterStartIndex) {
    return delimeterStartIndex >= 2 && messagePattern.charAt(delimeterStartIndex - 2) == ESCAPE_CHAR;
  }

  // special treatment of array values was suggested by 'lizongbo'
  private static void deeplyAppendParameter(StringBuilder sbuf, Object o, Map<Object[], Object> seenMap) {
    if (o == null) {
      sbuf.append((String) null);
      return;
    }
    if (!o.getClass().isArray()) {
      safeObjectAppend(sbuf, o);
    }
    else {
      // check for primitive array types because they
      // unfortunately cannot be cast to Object[]
      if (o instanceof boolean[]) {
        booleanArrayAppend(sbuf, (boolean[]) o);
      }
      else if (o instanceof byte[]) {
        byteArrayAppend(sbuf, (byte[]) o);
      }
      else if (o instanceof char[]) {
        charArrayAppend(sbuf, (char[]) o);
      }
      else if (o instanceof short[]) {
        shortArrayAppend(sbuf, (short[]) o);
      }
      else if (o instanceof int[]) {
        intArrayAppend(sbuf, (int[]) o);
      }
      else if (o instanceof long[]) {
        longArrayAppend(sbuf, (long[]) o);
      }
      else if (o instanceof float[]) {
        floatArrayAppend(sbuf, (float[]) o);
      }
      else if (o instanceof double[]) {
        doubleArrayAppend(sbuf, (double[]) o);
      }
      else {
        objectArrayAppend(sbuf, (Object[]) o, seenMap);
      }
    }
  }

  private static void safeObjectAppend(StringBuilder sbuf, Object o) {
    try {
      sbuf.append(o.toString());
    }
    catch (Throwable t) {
      System.err.println("LOGGER: Failed toString() invocation on an object of type [" + o.getClass().getName() + "]");
      System.err.println("Reported exception:");
      t.printStackTrace();

      sbuf.append("[FAILED toString()]");
    }

  }

  private static void objectArrayAppend(StringBuilder sbuf, Object[] a, Map<Object[], Object> seenMap) {
    sbuf.append('[');
    if (!seenMap.containsKey(a)) {
      seenMap.put(a, null);
      final int len = a.length;
      for (int i = 0; i < len; i++) {
        deeplyAppendParameter(sbuf, a[i], seenMap);
        if (i != len - 1) sbuf.append(", ");
      }
      // allow repeats in siblings
      seenMap.remove(a);
    }
    else {
      sbuf.append("...");
    }
    sbuf.append(']');
  }

  private static void booleanArrayAppend(StringBuilder sbuf, boolean[] a) {
    sbuf.append('[');
    final int len = a.length;
    for (int i = 0; i < len; i++) {
      sbuf.append(a[i]);
      if (i != len - 1) sbuf.append(", ");
    }
    sbuf.append(']');
  }

  private static void byteArrayAppend(StringBuilder sbuf, byte[] a) {
    sbuf.append('[');
    final int len = a.length;
    for (int i = 0; i < len; i++) {
      sbuf.append(a[i]);
      if (i != len - 1) sbuf.append(", ");
    }
    sbuf.append(']');
  }

  private static void charArrayAppend(StringBuilder sbuf, char[] a) {
    sbuf.append('[');
    final int len = a.length;
    for (int i = 0; i < len; i++) {
      sbuf.append(a[i]);
      if (i != len - 1) sbuf.append(", ");
    }
    sbuf.append(']');
  }

  private static void shortArrayAppend(StringBuilder sbuf, short[] a) {
    sbuf.append('[');
    final int len = a.length;
    for (int i = 0; i < len; i++) {
      sbuf.append(a[i]);
      if (i != len - 1) sbuf.append(", ");
    }
    sbuf.append(']');
  }

  private static void intArrayAppend(StringBuilder sbuf, int[] a) {
    sbuf.append('[');
    final int len = a.length;
    for (int i = 0; i < len; i++) {
      sbuf.append(a[i]);
      if (i != len - 1) sbuf.append(", ");
    }
    sbuf.append(']');
  }

  private static void longArrayAppend(StringBuilder sbuf, long[] a) {
    sbuf.append('[');
    final int len = a.length;
    for (int i = 0; i < len; i++) {
      sbuf.append(a[i]);
      if (i != len - 1) sbuf.append(", ");
    }
    sbuf.append(']');
  }

  private static void floatArrayAppend(StringBuilder sbuf, float[] a) {
    sbuf.append('[');
    final int len = a.length;
    for (int i = 0; i < len; i++) {
      sbuf.append(a[i]);
      if (i != len - 1) sbuf.append(", ");
    }
    sbuf.append(']');
  }

  private static void doubleArrayAppend(StringBuilder sbuf, double[] a) {
    sbuf.append('[');
    final int len = a.length;
    for (int i = 0; i < len; i++) {
      sbuf.append(a[i]);
      if (i != len - 1) sbuf.append(", ");
    }
    sbuf.append(']');
  }

}
